Product Manuals
Introduction
SBS (styrene–butadiene–styrene) modified bitumen membranes are polymer-enhanced bituminous sheets reinforced with polyester, fiberglass, or HDPE. They are widely used for retaining walls, podiums, terraces, and tanking applications, and are supplied as torch-applied, self-adhesive, or hot-mopped rolls.
Advantages
- Long track record and proven performance
- Good adhesion to primed concrete
- Self-adhesive options eliminate flame risk
- Robust against backfill pressure with good tear and puncture resistance
- Chemical resistance to chlorides, sulfates, and dilute acids/alkalis
- Low temperature flexibility
Limitations
- Requires dry, smooth, primed substrates
- Seams are critical and require QA checks
- Torch application poses fire risk in confined areas
- Less suitable than fully bonded HDPE for deep basements with high hydrostatic head
- Requires protection layers against mechanical damage
Types
- Self-adhesive (cold-applied) membranes
- Torch-applied membranes
- Hot-mopped systems
- Thickness range typically 1.5–4.0 mm
Application / Method Statement (Self-Adhesive Summary)
- Surface preparation: Sound, clean, dry, and primed substrate. Repair honeycombs and ensure level surface.
- Priming: Bituminous primer applied at recommended coverage, allow to dry.
- Laying: Align rolls, maintain side laps ≥ 50 mm and end laps ≥ 100 mm. Peel release film and press from center outward to expel air.
- Detailing: Treat corners, grooves, and penetrations with pre-cuts. Terminate into chases and seal.
- Protection: Provide screed, dimple board with geotextile, or other protection before backfill or topping.
Decision Guide
- Positive-side retaining walls and podium slabs → SBS membranes with mechanical protection
- Confined or flame-restricted areas → self-adhesive systems
- High hydrostatic pressure or confined basements → prefer fully bonded HDPE or spray-applied PU systems
Acceptance criteria
Substrate dry, smooth, and primed. Primer coverage within specified range.
Laps achieved. ≥ 50 mm side and ≥ 100 mm end laps (or per datasheet).
Full adhesion confirmed by rolling and absence of air pockets.
Protection layer installed before backfill or topping.
QA records captured. Lap checks, primer logs, photos.
Video
SpecX Masterclass: SBS Modified Bitumen Membrane — Coming soon